This invention relates in general to a hog holder apparatus and, more particularly, to a hog holder apparatus having an improved locking device for preventing a threaded rod from being advanced into a hollow tube.
Hog holder devices are conventionally used to restrain hogs by grasping the snout of the hog with a rope loop that can be pulled tight to securely grasp the snout. The rope loop typically is formed at the end of a rigid elongated tube by fixing one end of the rope to a flange projecting from an end of the tube. The rope is then threading the hollow interior of the tube and is fixed at its other end to a rod that is extendable within the hollow tube. Extension and retraction of the rod within the tube varies the size of the rope loop accordingly.
Conventional hog holder devices typically include a locking mechanism that must be released before the rope loop can be loosened. This locking mechanism is desirable because it releasably locks the rope loop in place once it has been applied to the hog's snout. The user of the hog holder device is then able to restrain the hog merely by grasping the hollow tube, leaving the other hand free to administer injections or otherwise attend to the hog. The locking mechanism typically is formed by a rectangular locking plate that is captured within a curved flange at the end of the hollow tube opposite from the rope loop. The extendable rod passes through a hole in the locking plate, with the hole being sized slightly larger than the diameter of the rod. When the locking plate is positioned perpendicular to longitudinal axis of the rod, the rod may be freely advanced and retracted longitudinally through the hole in the locking plate. However, when the locking plate is tilted slightly from the perpendicular orientation in relation to the axis of the rod, the rod binds against the portion of the locking plate surrounding the hole and the locking plate, in turn, engages the end of the tube. The rod is thereby locked against further advancement into the tube and corresponding increase in the size of the rope loop until such time as the locking plate is manually returned to the perpendicular released position. The locking plate is positioned in the curved flange in a manner such that the locking plate is normally maintained in the tilted, locked position. However, because the locking plate is free to move away from the tube end within the confines of the curved flange, the rod may still be retracted within the tube to tighten the rope loop by exerting a retracting force on the rod without having to manually manipulate the locking plate back to the perpendicular position.
While hog holding devices of the type described above are generally reliable, in some instances the rope loop may inadvertently be permitted to expand when the locking plate slips along the smooth surface of the rod, such as when moisture is present on the rod, or when the locking plate is displaced from the tilted, locked position. A need has thus developed for a hog holding device that more securely engages the locking plate against the rod to prevent accidental release of the hog.